Rocket retaining mechanism for launcher tubes

ABSTRACT

Rocket launcher-tube rocket retaining mechanism of the detent type for rockets with a latching rim having a circumferential groove and foldable stabilizing fins. A latching arm is rotatably mounted at one of its ends to a mounting plate secured over an opening in the tube sidewall, spring means urging the free end of the arm into the tube. The arm defines an inwardly extending latching tab spaced forward of a rear stop projection on the mounting plate, this space accommodating the rocket latching rim with the latching tab projecting into the rocket circumferential groove. The free end of the latching arm is oriented such that the blast issuing from an ignited rocket will impinge against it and rotate it radially outward to withdraw the latching tab from the rocket circumferential groove and free the rocket for forward flight. The shape of the latching tab provides positive latching, a forward movement tendency of the rocket causing an increase in the latching force due to an over-center action.

United States Patent 1 3,659,493 Wissner 1 May 2, 1972 [54] ROCKETRETAINING MECHANISM Primary Examiner-Samuel W. Engle FOR LAUNCHER TUBESAttorney-Victor G. Laslo [72] Inventor: Irving E. Wissner, Santa Monica,Calif. [57] ABSTRACT [73] Asslgnee: Los Angeles Cahf Rocketlauncher-tube rocket retaining mechanism of the de- [22] Filed: Jan. 16,1970 tent type for rockets with a latching rim having a circumferentialgroove and foldable stabilizing fins. A latching arm is [21] 3346rotatably mounted at one of its ends to a mounting plate secured over anopening in the tube sidewall, spring means [52] U.S. Cl ....89/ 1.807,89/1.8l4, 89/1 .816 urging the free end of the arm into the tube. Thearm defines [51] Int. Cl ..F4lf 3/04 an inwardly extending latching tabspaced forward of a rear [58] Field of Search..89/1.806,l.807,1.816,1.814, Stop projection n the mounting plate, thisspace accom- 89/1-808 modating the rocket latching rim with the latchingtab projecting into the rocket circumferential groove. The free end ofthe [56] Reel'ences Cited latching arm is oriented such that the blastissuing from an ignited rocket will impinge against it and rotate itradially out- UNITED STATES PATENTS ward to withdraw the latching tabfrom the rocket circum- 2,848,925 8/1958 Hood ..89/1.806 ferentia]groove and free the rocket for forward flight. The 3,412,640 1 1968 Nasht r a x shape of the latching tab provides positive latching. a forward2,450,929 1949 P movement tendency of the rocket causing an increase inthe 2,938,431 l 960 DIXO" 89/1307 latching force due to an over-centeraction. 3,059,543 10/1962 Manz et al. ..89/l.807

8 Claims, 7 Drawing Figures w i V A a 1 a? "a? 51; T"; a; 4 14' ll 7 V.

l I. If) 1 15 m 40% 15 4 Patented May 2, 1972 2 Sheets-Sheet l ROCKETRETAINING MECHANISM FOR LAUNCHER TUBES BACKGROUND OF THE INVENTION Inthe current state of rocket weaponry, certain types of 5 rockets areprovided at their rear ends with a latching rim adjacently behind acircumferential groove and ahead of a rearwardly opening nozzle ornozzles, the launches for these rockets usually including a plurality ofclustered launcher tubes, the launcher tubes being provided withlatching mechanisms which engage the rocket latching rim to securelyretain the rockets in the tubes and release them upon firing.

Latching mechanisms have been developed around the use of an elongatelatching arm secured at one of its ends to the rear portion of thelauncher tube, a biasing force urging its free end inwardly into thetube. The arm defines an inwardly extending latching tab for engagementwith the rocket circumferential groove to secure the rocket in the tubewith the free end of the arm adjacently behind a rocket nozzle. When therocket motor is ignited, the ensuing blast from the nozzle impingesagainst the free end of the latching arm to rotate it outwardly againstthe biasing force and withdraw the latching tab from the rocketcircumferential groove, thereby freeing the rocket for forward flight.

In the typical prior art latching arm embodiments the biasing force isprovided by the resiliency of the latching arm itself, sometimes inconjunction with a reinforcing leaf spring running along the outside ofthe latching arm and secured by the same fastening means which mountsthe arm to the tube. Typical prior art mounting comprises riveting orotherwise securing the mounting end of the latching arm directly to thetube sidewall, the free end of the latching arm projecting through asuitably sized opening in the tube sidewall.

However, these prior art latching mechanisms, although sound inprinciple, are not without their attendant disadvantages. Reliance uponarm resiliency significantly affects not only reliability and usefullife, but also reproducibility to any but the broadest tolerances andparameters. Since the latching arm is directly exposed to the rocketblast, the heat and ablation resistance characteristics of the latchingarm material become important, as well as its resiliency over the widetemperature range encountered. Furthermore, surface hardnesscharacteristics and costs are also factors to be considered. Obviously,compromises are necessary, which compromises themselves result inserious degradation of device reliability and useful life. Due to thenecessary curvature of the latching arm and bending relief notches atthe point of curvature, it is extremely difficult to consistentlyreproduce latching arms having a similar degree of resiliency so thatthe same deflecting force would properly operate each arm, even when anauxiliary leafspring is used.

Another factor affecting device reliability is the latching tabconfiguration of the prior art latching arms wherein the latching tabsurfaces operate to limit both forward and rearward movement of acarried rocket, any rotation of the latching arm thereby causingmovement of both of these limited surfaces. Radially inward movement ofthe latching arm resulting from a forward movement of the rocket (beforefiring) would tend to apply a forward directed pressure against therearward surface of the rocket latching rim, the pressure applied to thelatching arm by the rearward surface of the rocket latching rim upon arearward movement of the rocket tending toward a radially outward ordisengaging movement of the latching arm. The present invention isdirected toward an improved rocket latching mechanism obviating theaforementioned disadvantages.

SUMMARY OF THE INVENTION Although the present invention rocket latchingmechanism utilizes the aforementioned general operating principlewherein an elongate latching arm is secured at one of its ends, abiasing force urging its free end inwardly into the tube, the blast froman ignited rocket being utilized to provide the desired latchdisengaging force, a different form of structure results in an improveddevice which provides'a significant advance in the art. The presentinvention rocket retaining detent mechanism comprises three maincomponents; a mounting plate, a rigid latching arm and separate springmeans. The mounting plate is secured to the rocket tube covering theopening in the tube sidewall through which the latching arm projects,the plate having an inwardly facing depression extending axiallyalongside a radially inward projection defining a forward facingabutting surface projecting inwardly into the tube for engaging therearward surface of the rocket latching rim. The latching arm is mountedat one of its ends within the mounting plate depression, theintermediate portion of the latching arm defining an inwardly extendinglatching tab with a curved camming surface extending between arearwardly inclined forward edge and a generally radial rear edge, therear edge of the latching tab being forwardly spaced from the abuttingsurface of the mounting plate projection a distance slightly greaterthan the thickness of the rocket latching rim. The spring meansproviding the radially inward biasing force for the latching arm isdisposed within the mounting plate depression, and in presentlypreferred embodiments comprises a leaf spring or a torsion coil spring.

The configuration of the latching tab forward and rearward edges andcamming surface function so that as a rocket is in serted into the tubethe rocket latching rim will engage the rearwardly inclined forward edgeof the latching tab to rotate the latching arm radially outward as therim slides across the latching tab forward edge and camming surface. Asthe latching rim leaves the camming surface and passes over the rearedge of the latching tab, the pressure of the spring means urges thelatching arm radially inwardly into the rocket circumferential groove toretain the rocket in a predetermined carrying position. When the rocketis in this predetermined position further rearward displacement of therocket in the tube is prevented by engagement of the rearward surface ofthe rocket latching rim with the forward facing abutting surface of themounting plates radially inward projection, forward displacement of therocket in the tube being limited by engagement of the latching rimforward surface with the rear edge of the latching tab.

The use of a rotatably mounted, rigid latching arm and separate springresults in more positive and reliable action and enables optimization ofoperating and material characteristics for each application. Latchdisengaging force can be accurately adjusted by determination of thespring tension, the spring material being selected on the basis ofoperating environments and desired service life. Since the latching armis of a rigid type its temperature and surface hardness characteristicscan be optimized, resiliency no longer being required. Theaforementioned spring and latching arm parameters and characteristicscan now be specified to quite close tolerances and the latchingmechanism "customized" for various applications on a mass reproductionbasis.

Removal of the rocket rearward displacement limiting function (when therocket is in the predetermined carrying position) from the moveablelatching arm results in a more positive and reliable latching action.Rearward movement of a rocket from the determined carrying position doesnot cause rotation of the latching arm, rearward movement now beinglimited by the abutting surface on the latching plate projection, nordoes forward movement of the rocket result in a forward directed forcebeing applied to the rearward surface of the rocket latching rim.

Removal of the rocket rearward displacement limiting function from thelatching arm also enables a positive latching due to the over-centeraction resulting from the radially inward rotation of the latching armcaused by the pressure exerted by the forward surface of the rocketlatching rim upon the generally radial rear edge of the latching tabupon forward movement of the rocket prior to firing, the radially inwardrotation of the latching arm increasing the latching pressure. Becauseof this self-latching feature, much less spring biasing is required thanin the prior art mechanisms wherein the spring biasing force is reliedupon to maintain proper latch engagement upon axial movements of therocket before launching. Upon firing of the rocket and subsequentradially outward rotation of the latching arm caused by the force fromthe exhaust jet, the rocket latching rim will engage the latching tabcamming surface, forward movement of the rocket then causing thelatching rim to override the latching tab by forcing it outward as therim slides across the tab camming surface, thereby completing the latchrelease.

It is therefore the primary object of the present invention to providerocket launcher tube rocket retaining mechanisms of improved operationand reliability.

It is another object of the present invention to provide rocketretaining mechanisms of the type stated, characterized by increaseduseful life and economical reproducibility to significantly closertolerances.

Further objects and advantages of the invention will become apparentfrom the following description and drawings in which presently preferredembodiments are illustrated by way of example, the scope of theinvention being indicated in the accompanying claims.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 of the drawing shows anelevation view, in cross-section, of the rear portion of a rocketlauncher tube, including one presently preferred embodiment of thepresent invention detent mechanism, with a 2.75 inch FFAR type rocketloaded into position in the tube;

FIG. 2 is a view taken along the line 22 of FIG. 1;

FIG. 3 is a perspective view of the detent mechanism shown in FIG. 1;

FIG. 4 is a view taken along the line 4-4 of FIG. 1;

FIG. 5 is an elevation view, in cross-section, of the rear por' tion ofa rocket launcher tube, including another presently preferred embodimentof the present invention detent mechanism, with a MK 66 type rocketloaded into position in the tube;

FIG. 6 is a view taken along the line 6-6 of FIG. 5; and

FIG. 7 is a perspective view of the detent mechanism shown in FIG. 5.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Turning first to FIG. 3 of thedrawing, there is shown a perspective view of the presently preferredembodiment of a detent mechanism for use with the current 2.75 inch FFARrocket configuration. The three main components of the detent mechanism;a mounting plate, a latching arm and a spring, are generally indicatedby the respective reference numerals 10,30 and 50.

The mounting plate 10 is of elongate configuration, having an innersurface 14 transversely concave in accordance with the curvature of theouter wall of the rocket tube to which it is to be secured. The mountingplate is provided with suitable mounting holes 11, 12 and 13 near itsends to accommodate rivets or other suitable fasteners for securing theplate to the rocket tube. The central portion of mounting plate 10defines an axially extending depression 15 which faces inwardly when themounting plate is secured to a rocket tube, i.e., depression 15 is aradially outward depression. A pair of transversely aligned lugs 16 arepositioned one on either side of depression 15, the lugs projecting fromthe concave inner surface 14. Each of the lugs 16 has a transverse edgewhich defines an abutting surface 17 for engaging the rearward surfaceof the rocket latching rim, as will be hereinafter explained.

The latching arm generally defines a straight end portion 31, anintermediate portion 32 and a curved end portion 33. The arm 30 isrotatably mounted at its straight end portion 31 to the mounting plate10 within depression 15 by means of a transverse pin 34. Projecting fromthe intermediate portion 32 are a pair of transversely spaced latchingtabs 40, each tab defining a curved camming surface 41 extending betweenan inclined edge 42 and a perpendicular edge 43, the edge 43 beingsomewhat shorter than the edge 42. The end portion 33 is curved awayfrom the mounting plate 10 so as to project concavely inward into therocket tube, as indicated in FIG. 1.

FIG. 1 shows the rear end portion ofa rocket launcher tube 5 loaded witha 2.75 inch FFAR rocket, the rocket being generally indicated by thereference numeral 60. The rocket defines a circumferential latching rim61 adjacently behind a circumferential groove 62, the latching rimhaving flat forward and rearward surfaces respectively indicated by thereference numerals 66 and 67. Four radially spaced rearwardly openingnozzles 63 project rearwardly from the latching rim between fourfoldable stabilizing fins 65, as can best be seen in FIGS. 1 and 2. Thefins are pivotally mounted at their forward ends, and retained in theirretracted position of FIG. 1 by means of a retaining plate 68 fitted tothe extreme rear ends of the fins, the retainer plate being formed froma suitable dielectric material and being centrally provided with arearwardly spacing electrical contact button 69. An arcuate shapedelectrical contact 70 is mounted to the tube 5, the contact button 69being urged thereagainst when the rocket is in the carrying positionshown in FIG. 1.

The latching arm is biased radially inwardly by means of the spring 50,which in the presently preferred form is a torsion coil spring. As shownin FIGS. 1-4 a coil 51 is provided with elongate end portions 52 and 53,the end portion 52 bearing against the bottom of mounting platedepression 15, the end portion 53 bearing against the lower surface ofthe latching arm 30.

The detent mechanism is secured to the rocket tube 5 by means of rivetsl8 fitted through the mounting holes l1, l2 and 13, with the depression15 in register with aperture 6 of the launcher tube. In this positionthe lugs 16 and the free end of the latching arm 30 project into theinside of the tube.

The latching tabs 40 are positioned on the arm intermediate portion 32such that when the arm is in the position shown in FIG. 1, the spacebetween the forward facing abutting surfaces 17 of the mounting platelugs 16 and the rear edges 43 of the latching tabs 40 is slightlygreater than the thickness of the rocket latching rim 61, the latchingrim being accommodated within this space. As can also best be seen inFIG. 1, the latching tabs 40 are dimensioned to fit within the rocketcircumferential groove 62, the rear edges 43 being in a substantiallyradial orientation when the latching mechanism is engaged to maintainthe rocket in its carrying position within the rocket tube.

When the launcher tube 5 is empty, the spring 50 biases the curved endportion of the latching arm 30 away from the depression 15 and lugs 16to the approximate position shown in FIG. 3. Upon loading of the rocket60 into the launcher tube 5, by inserting it into the forward end of thetube and urging it rearwardly therethrough, the rear portion of therocket will contact the inwardly projecting latching arm 30 and rotateit radially outward as the rocket is pushed 2, into the tube. Should therocket happen to be aligned so that one of the fins 65 strikes thelatching arm 30 as the rocket is being inserted into the tube the armwill prevent complete insertion of the rocket into the tube. In suchcase, the tube is merely withdrawn a small amount, slightly rotated andthen reinserted, whereupon the fins will straddle the latching arm 30and the mounting plate lugs 16. However, orientation of each of thelauncher tubes in a cluster so that the latching arms project verticallyupwards, as illustrated in FIG. 0, obviates the necessity for a specificrocket orientation during loading, it being merely necessary to rotatethe rocket so that the rear edges ofthe fins are in a X" orientation.

As the rocket is inserted into the tube in the approximate alignmentshown in FIG. 2, the latching rim rearward surface 67 will contact thelatching tab inclined edges 42 and begin radially outward rotation ofarm 30, further rearward displacement of the rocket in the tube thencontinuing the radially outward rotation of the latching arm as thelatching rim 61 slides across the camming surfaces 41, this deflectedposition of the latching arm being shown in phanthom in FIG. 1. Thepressure of spring 50 rotates the latching arm radially inwardly as thelatching rim passes over the camming surfaces 41 and the rear edges 43of the latching tabs 40 to urge the latching tabs into the rocketcircumferential groove 62 to retain the rocket in the predeterminedcarrying position, as shown in FIG. 1. In this predetermined carryingposition engagement of the rearward surface 67 of the rocket latchingrim with the forward facing abutting surfaces 17 of the mounting platelugs prevents further rearward displacement of the rocket in the tube,forward displacement of the rocket in the tube being limited byengagement of the rocket latching rim forward surface 66 with the thenradially oriented rear edges 43 of the latching tabs. The radialorientation of the rear edges, acting in conjunction with the somewhatlower mounting of the pin 34 which determines the latching arm axis ofrotation, provides the aforementioned over-center action wherein forwarddisplacement of the rocket, before firing, will cause tighter latchingengagement due to further radially inward rotation of the latching armresulting from the pressure of the latching rim against the rear edges43 of the latching tabs.

In the rocket carrying position, the rearwardly extending curved endportion 33 of the latching arm projects into the tube adjacent and tothe rear of one of the nozzles, the arm being oriented such that theblast issuing from an ignited rocket will impinge against the curved endportion 33 to rotate the latching arm radially outward, therebywithdrawing the latching tabs from the rocket circumferential groove andfreeing the rocket for forward flight. Upon ignition of the rocket motorthe latching tab will restrain forward movement of the rocket until themotor exhaust exerts sufficient force against the latching arm curvedend portion 33 to cause the arm to begin to rotate radially outward. Atthe beginning of radial outward movement of the latching arm the rocketwill be moved very slightly rearwardly due to pressure of the rear edges43 of the latching tabs against the rocket latching rim. Furtherrotation of the latching arm will bring the curved camming surfaces 41to bear against the forward surface 66 of the latching rim, whereuponthe rocket will begin to move forward and override the latching tabs dueto the curved configuration of the camming surfaces.

For proper latch release, the curved end portion 33 of the latching armshould present a transverse surface for the rocket blast to impingeagainst. For convenience in manufacturing, it is presently preferred tofabricate the latching arm as an integral structure forming a generallychannel-shaped cross section as shown, with the latching tabs on thechannel flanges and with the channel web portion presenting the desiredtransverse surface for impingement of the rocket blast.

Turning now to FIGS. 5, 6 and 7 of the drawing there are shown variousviews of the present invention rocket latching mechanism adapted for usein a launcher for rockets of the socalled MK 66 type, these rocketshaving a single, central nozzle, curved stabilizing fins hinged along alongitudinal edge, and an electrical contact ring ring disposed withinthe rocket circumferential groove. FIG. 5 shows the rear end portion ofa rocket launcher tube 105 loaded with a MK 66 rocket, the rocket beinggenerally indicated by the reference numeral 160. The rocket 160 definesa circumferential latching rim 161 adjacently behind a circumferentialgroove 162, the latching rim having flat forward and rearward surfacesrespectively indicated by the reference numerals 166 and 167. Set intothe surface of circumferential groove 162 is an annulus 168 ofelectrical insulating material, an electrical contact ring 169 being setinto the surface of the insulating annulus whereby the contact ring 169is insulated from the rocket body.

A single, rearwardly opening rocket nozzle 170, having a rifled innersurface, terminates at the rearward surface 167 of the rocket latchingrim. Three folding fins 165 of curved cross-section, are hingedlymounted to the rocket body ahead of the rocket latching rim 161 andgroove 162. Thus, unlike the 2.75 inch FFAR rocket, the latching rim ofthe MK 66 rocket is at the extreme rear end of the rocket. Onelogitudinal edge of each of the fins 165 is provided with an elongatenotch 164, the fin being hingedly mounted by means of a pin 163extending through the notch. Each of the fins is normally springloadedto an open position (indicated in phantom in FIG. 6) by means of atorsion coil spring 171. For loading into the rocket tube the fins arefolded circumferentially inward against the spring pressure, the finsbeing urged rearwardly so that each fin rear edge enters a retainingslot 172 in the rocket body. The fins are held in this closed positionwhile loading the rocket into the tube, the inner tube walls thenpreventing the fins from flying open. Rearward movement of the fins intothe retaining slots 172 causes compression of the coil springs 171 sothat when the rocket leaves the tube upon firing, logitudinal expansionof the coil springs urge the fins forward, the fins flying open whenthey clear the retaining slots 172.

Since electrical connections to the MK 66 rocket must be made to itscircumferential groove, an appropriate electrical contact is carried bythe latching arm of the detent mechanism. As in the previous embodiment,the detent mechanism generally comprises a mounting plate, a latchingarm and a spring, these components being generally indicated by therespective reference numerals 110, 130 and 150. The mounting plate issimilar to the mounting plate 10 of the hereinabove describedembodiment, the mounting plate 110 being of an elongate configurationand having an inner surface 114 transversely concave in accordance withthe curvature of the outer wall of the rocket tube. The mounting plateis provided with suitable mounting holes 111, 112 and 113 near its endsto accommodate rivets 118 which secure the plate to the rocket 105. Thecentral portion of mounting plate 110 defines an axially extending,radially outward depression 115. A pair of transversely aligned lugs 116are positioned one on either side of depression 115, the lugs projectingfrom the concave inner surface 114. Each of the lugs 116 has atransverse edge which defines an abutting surface 117 for engaging therearward surface of the rocket latching rim.

The latching arm 30 generally defines a straight end portion 131, anintermediate portion 132 and a curved end portion 133. The arm 130 isrotatably mounted at its straight end portion 131 to the mounting plate110 within depression by means of a transverse pin 134. Projecting fromthe intermediate portion 132 are a pair of transversely spaced latchingtabs 140, each tab defining a curved camming surface 141 extendingbetween an inclined edge 142 and a perpendicular edge 143, the edge 143being somewhat shorter than the edge 142. The end portion 133 is curvedaway from the mounting plate 110 so as to project concavely inward intothe rocket tube, as indicated in FIG. 5.

Latching arm is of generally channel-shaped cross-section having anelectrical contact partially encapsulated in an insulating body 144disposed within the channel at the straight end portion 131. The contact145 defines an angular end portion 145a projecting from the insulatingbody 144 and extending between and slightly higher than the latchingtabs so that it will contact the rocket electrical contact ring 169 whenthe rocket is in its predetermined carrying position, as shown in H6. 5.An insulated electrical lead 146 has one of its ends connected to theelectrical contact 145, the other of its ends projecting from the end ofthe insulating body 144 for connection to external electrical circuitry.Another electrical lead 147 has one of its ends connected to the rocketcontact ring 169, the lead extending through an insulating bushing 148into the interior of the rocket nozzle for connection to the rocketfiring circuitry.

The latching am is biased radially inwardly by means of the spring 150,which in this embodiment is in the form of an elongate leaf springhaving an irregularly curved end portion 151 for mounting of the springby snapping it under the transverse pin 134, whereby the end of thespring is compressed between the transverse pin and the bottom of themounting plate depression 115. The free end of the leaf spring bearsagainst the lower surface of the latching arm 130, the spring 150 functioning in the same manner as the spring 50 in the hereinabovedescribed embodiment.

As before, the latching tabs are positioned on the latching armintermediate portion such that when the rocket is in the predeterminedposition in the tube, the space between the forward facing abuttingsurfaces of the mounting plate lugs and the rear edges of the latchingtabs is slightly greater than the thickness of the rocket latching rim,the latching rim being accommodated within this space. As can be seen inFIG. 5, the latching tabs 140 are dimensioned to fit within the rocketcircumferential groove 162, the rear edges 143 being in a substantiallyradial orientation when the latching mechanism is engaged to maintainthe rocket in its predetermined carrying position.

Since the rearward surface 167 also defines the rear extremity of therocket, no special care need be taken to rotationally orient the rocketupon loading into the tube. As the rocket is loaded into the tube andpushed rearwardly, the rearward surface 167 will contact the inclinedforward edges 142 of the latching tabs 140 to rotate the latching armradially outward, the latching rim then sliding across the forward edges142, the projecting tip of contact 145 and the camming surfaces 141. Thepressure of spring 150 rotates the latching arm radially inwardly as thelatching rim passes over the camming surfaces 141 and the rear edges 143of the latching tabs 140 to urge the latching tabs into the rocketcircumferential groove 162 to retain the rocket in the predeterminedcarrying position.

In the rocket carrying position, the rearwardly extending curved endportion 133 of the latching arm projects into the tube so that the blastwhich issues from nozzle 170, upon ignition of the rocket, will impingeagainst the curved end portion 133 to rotate the latching arm radiallyoutward, thereby withdrawing the latching tabs from the rocketcircumferential groove and freeing the rocket for forward flight. Thefunctioning of the latching mechanism is basically identical to thathereinabove described with respect to the embodiment shown for use withthe 2.75 inch FFAR rocket.

The presently preferred latching arm form, wherein the channel-shapedcross section provides high strength and rigidity, is relatively easilyand economically fabricable by a stamping operation, as is the presentlypreferred form of the mounting plate. Other latching arm formsincorporating high strength, the specified latching tab configuration,and the transverse paddle" surface of the arm's free end will also beapparent, as will application of the present invention principles to theretention of other classes and types of rockets. By flaring out thecurved end of the latching arm to increase the transverse paddle"surface, proper release can be assured for rockets of lower impulse.Thus, although the invention has been described with a certain degree ofparticularity, it is understood that the foregoing description has beenby way of example only and that other combinations and arrangements ofparts will be within the scope of the invention. For example, althoughit is convenient to form two latching tabs on the latching arm inaccordance with the presently preferred embodiment, proper latchingfunctioning could be achieved with an arm embodiment utilizing only asingle latching tab. It is presently preferred to utilize two of thelugs 16 on the mounting plate instead of just one since the two spacedapart lugs present excessive rotation of the 2.75 inch FFAR rocket whilebeing carried in the launching tube.

Thus there has been described improved rocket launching retainingmechanisms which feature improved reliability and useful life, whilebeing simply and inexpensively fabricable.

What is claimed is:

1. In a rocket launcher tube for carrying and launching an elongatetubular rocket having a circumferential latching rim adjacently behind acircumferential groove and ahead of a rearwardly opening nozzle, animproved rocket retaining detent mechanism comprising:

a. A mounting plate secured to said tube covering an axially extendingaperture in the tube sidewall, said plate having a radially outwarddepression extending axially and a radially inward projection defining aforward facing abutting surface projecting inwardly into said tube forengaging the rearward surface of the rocket latching rim;

b. An elongate, rigid latching arm defining an intermediate portionextending between a straight end portion and an angular end portion,means rotatably mounting said arm at one of its end portions to saidmounting plate within said depression and with its other end portionextending rearwardly and projecting inwardly into said tube, saidintermediate portion defining an inwardly extending latching tab with acurved camming surface extending between a rearwardly inclined forwardedge and a generally radial rear edge, the rear edge of said latchingtab being forwardly spaced from the abutting surface of said mountingplate projection a distance at least as great as the thickness of therocket latching rim; and

c. Spring means disposed within the mounting plate depression for urgingsaid latching arm radially inwardly, so that as a rocket is insertedinto said tube the rocket latching rim will engage the rearwardlyinclined forward edge of said latching tab to rotate the latching armradially outward as the rim slides across the latching tab forward edgeand camming surface, the pressure of said spring means rotating saidlatching arm radially inwardly as said latching rim passes over saidcamming surface and the rear edge of the latching tab to urge thelatching tab into the rocket circumferential groove and retain saidrocket in a predetermined position wherein engagement of the rearwardsurface of the rocket latching rim with the forward facing abuttingsurface of the mounting plate radially inward projection preventsfurther rearward displacement of the rocket in the tube and whereinforward displacement of the rocket in the tube is limited by engagementof the latching rim forward surface with the rear edge of said latchingtab, the rearwardly extending end portion of said latching armprojecting into the tube adjacent and to the rear of the nozzle when therocket is in the predetermined position and oriented such that the blastissuing from an ignited rocket will impinge thereagainst to rotate saidlatching arm radially outward to withdraw said latching tab from therocket circumferential groove and free the rocket for forward flight.

2. An improved detent mechanism as defined in claim 1, wherein saidlatching arm is mounted at its straight end portion to said mountingplate and with its angular end portion extending rearwardly.

3. An improved detent mechanism as defined in claim 2, wherein theangular end portion of said latching arm is curved, said latching armbeing mounted with its curved end portion projecting concavely inwardlyinto said tube.

4. An improved detent mechanism as defined in claim 1, wherein saidmounting plate defines a radially outward depression extending axiallybetween two radially inward projections, each defining a forward facingabutting surface projecting inwardly into said tube for engaging therearward surface of the rocket latching rim, and wherein the rear edgeof said latching tab is forwardly spaced from the abutting surfaces ofsaid mounting plate projections a distance slightly greater than thethickness of the rocket latching rim.

5. An improved detent mechanism as defined in claim 4, wherein at leastthe intermediate portion of said latching arm is of generallychannel-shaped cross section, each flange of the channel defining asubstantially identical inwardly extending latching tab with a curvedcamming surface extending between a rearwardly inclined forward edge anda generally radial edge, the rear edge of each of said latching tabsbeing forwardly spaced from the abutting surface of said mounting plateprojection a distance slightly greater than the thickness of the rocketlatching rim.

6. An improved detent mechanism as defined in claim 1, further includingelectrical contact means mounted to said latching arm and insulatedtherefrom.

8. An improved detent mechanism as defined in claim 7, wherein saidelectrical contact means is partially encapsulated in a body ofelectrical insulating material in the straight end portion of saidlatching arm to electrically insulate said electrical contact means fromsaid latching arm.

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1. In a rocket launcher tube for carrying and launching an elongatetubular rocket having a circumferential latching rim adjacently behind acircumferential groove and ahead of a rearwardly opening nozzle, animproved rocket retaining detent mechanism comprising: a. A mountingplate secured to said tube covering an axially extending aperture in thetube sidewall, said plate having a radially outward depression extendingaxially and a radially inward projection defining a forward facingabutting surface projecting inwardly into said tube for engaging therearward surface of the rocket latching rim; b. An elongate, rigidlatching arm defining an intermediate portion extending between astraight end portion and an angular end portion, means rotatablymounting said arm at one of its end portions to said mounting platewithin said depression and with its other end portion extendingrearwardly and projecting inwardly into said tube, said intermediateportion defining an inwardly extending latching tab with a curvedcamming surface extending between a rearwardly inclined forward edge anda generally radial rear edge, the rear edge of said latching tab beingforwardly spaced from the abutting surface of said mounting plateprojection a distance at least as great as the thickness of the rocketlatching rim; and c. Spring meAns disposed within the mounting platedepression for urging said latching arm radially inwardly, so that as arocket is inserted into said tube the rocket latching rim will engagethe rearwardly inclined forward edge of said latching tab to rotate thelatching arm radially outward as the rim slides across the latching tabforward edge and camming surface, the pressure of said spring meansrotating said latching arm radially inwardly as said latching rim passesover said camming surface and the rear edge of the latching tab to urgethe latching tab into the rocket circumferential groove and retain saidrocket in a predetermined position wherein engagement of the rearwardsurface of the rocket latching rim with the forward facing abuttingsurface of the mounting plate radially inward projection preventsfurther rearward displacement of the rocket in the tube and whereinforward displacement of the rocket in the tube is limited by engagementof the latching rim forward surface with the rear edge of said latchingtab, the rearwardly extending end portion of said latching armprojecting into the tube adjacent and to the rear of the nozzle when therocket is in the predetermined position and oriented such that the blastissuing from an ignited rocket will impinge thereagainst to rotate saidlatching arm radially outward to withdraw said latching tab from therocket circumferential groove and free the rocket for forward flight. 2.An improved detent mechanism as defined in claim 1, wherein saidlatching arm is mounted at its straight end portion to said mountingplate and with its angular end portion extending rearwardly.
 3. Animproved detent mechanism as defined in claim 2, wherein the angular endportion of said latching arm is curved, said latching arm being mountedwith its curved end portion projecting concavely inwardly into saidtube.
 4. An improved detent mechanism as defined in claim 1, whereinsaid mounting plate defines a radially outward depression extendingaxially between two radially inward projections, each defining a forwardfacing abutting surface projecting inwardly into said tube for engagingthe rearward surface of the rocket latching rim, and wherein the rearedge of said latching tab is forwardly spaced from the abutting surfacesof said mounting plate projections a distance slightly greater than thethickness of the rocket latching rim.
 5. An improved detent mechanism asdefined in claim 4, wherein at least the intermediate portion of saidlatching arm is of generally channel-shaped cross section, each flangeof the channel defining a substantially identical inwardly extendinglatching tab with a curved camming surface extending between arearwardly inclined forward edge and a generally radial edge, the rearedge of each of said latching tabs being forwardly spaced from theabutting surface of said mounting plate projection a distance slightlygreater than the thickness of the rocket latching rim.
 6. An improveddetent mechanism as defined in claim 1, further including electricalcontact means mounted to said latching arm and insulated therefrom. 7.An improved detent mechanism as defined in claim 5 further includingelectrical contact means disposed within the latching arm channel andprojecting between and slightly more inwardly than said latching tabsfor engagement with an electrical contact in the rocket circumferentialgroove when the rocket is in said predetermined position.
 8. An improveddetent mechanism as defined in claim 7, wherein said electrical contactmeans is partially encapsulated in a body of electrical insulatingmaterial in the straight end portion of said latching arm toelectrically insulate said electrical contact means from said latchingarm.